/* counter.c */ /* {{{ * * Copyright (C) 2004 Nicolas Schodet * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Contact : * Web: http://perso.efrei.fr/~schodet/ * Email: * }}} */ #include "counter.h" #include /* +AutoDec */ /* -AutoDec */ /** Forward and reverse counter value. */ static uint8_t counter_l_frw, counter_l_rev, counter_r_frw, counter_r_rev; /** Last TCNT value. */ static uint8_t counter_l_old, counter_r_old; /** Initialize the counters. */ inline void counter_init (void) { /* Left counter. */ /* External, rising edge. */ TCCR2 = regv (FOC2, WGM20, COM21, COM20, WGM21, CS22, CS21, CS20, 0, 0, 0, 0, 0, 1, 1, 1); /* Right counter. */ /* Normal counter. */ //TCCR3A = 0; /* External, rising edge. */ TCCR3B = regv (ICNC3, ICES3, 5, WGM33, WGM32, CS32, CS31, CS30, 0, 0, 0, 0, 0, 1, 1, 1); /* Begin with safe values. */ counter_reset (); } /* Update counter, should be called as often as possible. */ inline void counter_update (void) { uint8_t c; /* Update left counter. */ c = TCNT2; if (PINE & _BV (4)) { PORTD &= ~0x40; counter_l_frw += c - counter_l_old; } else { PORTD |= 0x40; counter_l_rev += c - counter_l_old; } counter_l_old = c; /* Update right counter. */ c = TCNT3L; if (PINE & _BV (5)) { PORTD &= ~0x20; counter_r_frw += c - counter_r_old; } else { PORTD |= 0x20; counter_r_rev += c - counter_r_old; } counter_r_old = c; } /* Reset the counters. */ inline void counter_reset (void) { counter_l_frw = 0; counter_l_rev = 0; counter_l_old = TCNT2; counter_r_frw = 0; counter_r_rev = 0; counter_r_old = TCNT3L; }